The search giant said the move was the first step in transitioning from an "information agent" to a "knowledge agent."

"The Knowledge Graph enables you to search for things, people or places that Google knows about — landmarks, celebrities, cities, sports teams, buildings, geographical features, movies, celestial objects, works of art and more — and instantly get information that's relevant to your query," Amit Singhal, a senior vice president at Google, wrote.

Google is going to roll out the new feature slowly, but some users should begin seeing the feature this week. In practical terms, what's going to happen when you search on Google is that you'll see a separate "knowledge panel" on the right side of your regular search results that presents information about whatever your searching for.

Danny Sullivan, the search authority on the Web, says this is a "big change." Sullivan, who got a chance to test drive the feature, described his experience like this:

"A search for Star Trek brought up a panel that included a reference to Star Trek: Voyager, my favorite of all the series. Jumping to explore that, the Voyager box included a reference to Babylon 5, another favorite sci-fi show of mine. Jumping to that box, there was a reference to Claudia Christian, who wonderfully played one of the main characters in Babylon 5, Susan Ivanova. I surfed over for a look.

"If you've ever started reading a Wikipedia page and then gotten lost jumping from one topic to another, that's the experience I think many are about to discover with Google. You'll not only discover answers to factual questions, but you'll likely quickly explore more than you had planned and have fun doing it."

Google says that its search engine now contains 500 million objects and knows more than 3.5 billion facts "and relationships between these different objects." Google says it crawls more than public sources like Wikipedia and the CIA Factbook.